Mussels produce externalized tendons called byssal threads, which collectively serve as holdfasts. Byssal threads are coated with a thin protective cuticle (5-20 qm) that shields against abrasion by sand, chemical erosion, and microbial degradation, yet is flexible enough to accommodate strains of 0.7 by the fibrous byssal core. Mfp-1 is the primary structural protein of the byssal coating. It is also used commercially as a universal cell and tissue attachment factor and is being developed as a biomimetic tether for polymer attachment to surfaces. The present proposal aims to better understand the disposition, properties, and processing of mfp-1 in the byssal coating. This is considered essential for the intelligent synthesis and use of analogues for biomedical materials applications. Research aims include 1) the immunolocalization of mfp-1 in the mottled granules of the coating and foot; 2) mapping the elemental composition with the nanomechanical properties of the coating; measurement of metal binding affinities of fp-ls from four different mussel species (Mytilus galloprovincialis, M. californianus, Modiolus modiolus and Septifer bifurcatus) using an electrochemical chelate scale, and 4) investigating metal-induced collapse kinetics in adsorbed fp-ls by quartz crystal microbalance analysis in dissipation mode. In years 3 and 4, biomimetic coatings comprised of mfp-1 with and without added metal will be fabricated in vitro by solvent evaporation, coacervation, and controlled self-assembly processes. All films will be evaluated by macro- and nanomechanical tests, and their resistance to a diverse range of biochemical, thermal, and mechanical insults will be examined.